Transcript
The uses and abuses of statistics and numbers
4 out of 5 dentists recommend sugar-free gum
The odds of winning Lotto 6/49 are 1 in 13,983,816
79% of people don’t trust social networking sites
margin of error of 4%,
19 times out of 20
8% of people suffer from coulrophobia
A person’s statistical literacy is their ability to interpret and critically evaluate statistical information, and to communicate and discuss their reactions to this information.
Knowledge elements Dispositional elements
Literacy skillsStatistical knowledgeMathematical knowledgeContext knowledgeCritical Questions
Beliefs and AttitudesCritical Stance
Statistical LiteracyIddo Gal, “The Challenge of Developing Statistical Literacy, Reasoning and Thinking”, 2004. University of Haifa, Israel
You can use statistics to prove anything!14% of people know that.
M ss ng N mb rs
incalculable, uncounted, forgotten, etc.
Cnosfunig Nmuebrs
Averages, %’s, correlation, poor graphs etc.
Contentious numbers
Scary Numbers Scale, trends, risks
Authoritative Numbers
Results highlighted, ambiguities, ¿ authority ?
Magical Numbers
Numbers Games
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1965 1970 1975 1980 1985 1990 1995 2000
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1965 1970 1975 1980 1985 1990 1995 2000
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Suicides
Undetermined
Library at the British House of Commons
Statistical Literacy guide
Most important questions to ask:
Compared to what?
Since when?
Says who?
Many more questions…
Verbal Labels versus Numbers “The odds of something are: ...”
High
Quite certain
Small
Possible
Somewhat likely
Very low ...
What is a “high” risk? 90%? 1%? 1% may be “high” for test results you don’t
want to see 10% may be a “small possibility” for test
results you’re hoping to see Verbal labels are as confusing as numbers to
most patrons
90% vs 0.9 vs “9 in 10” Always compare numbers with the same
denominator (“9/10” “10” is denominator) Avoid probabilities, percentages Use frequency representation
The probability of successfully navigating an asteroid field is
approximately 0.0002688!
Best, J. Beyond calculation: quantitative literacy and critical thinking about public issues. Available from: http://www.maa.org/Ql/cvc/cvc-125-135.pdf. [Cited 25 Mar 2010].
Best, J. More damned lies and statistics. Berkeley, California: University of California Press; 2004.
Bolton, P. Statistical literacy guide: How to spot spin and inappropriate use of statistics. Available from: http://www.parliament.uk/commons/lib/research/briefings/snsg-04446.pdf. Dec 2009. [Cited 25 Mar 2010].
Burkell, J. What are the chances? Evaluating risk and benefit information in consumer health materials. J Med Libr Assoc 2004 Apr; 92(2):200-208.
Gal, I. Statistical literacy: meanings, components, responsibilities. In: Ben-Zvi D, Garfield J, editors. The Challenge of Developing Statistical Literacy, Reasoning and Thinking [electronic resource]. Dordrecht : Springer Science + Business Media, Inc.; 2005. p.47-78.
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